DCCD Subaru STi Explained

DCCD Subaru STi Explained:

Rear differential oil temperature warning light

When the DCCD system has detected abnormally high temperature of the rear differential oil, it notifies the driver of it through the warning light in the meter and, at the same time, frees the differential limiting force of the electromagnetic clutch LSD mechanism.

The center differential consists of three components: a planetary gear unit differential, a torque-sensitive mechanical LSD mechanism and an electromagnetic clutch LSD mechanism.

Engine output power input from the transmission driven shaft to the center differential goes through the planetary gear unit and is transmitted to the front wheel side from the drive pinion shaft penetrating through the driven shaft and to the rear wheel side from the transfer drive gear.

DCCD Subaru STi Explained:

Center Differential Mechanism

The planetary gear unit differential consists of a carrier containing six pinion gears, an internal gear mounted to inner periphery of the differential case and a sun gear mounted to the planetary shaft outer periphery.

DCCD: The planetary gear unit differential consists of a carrier containing six pinion gears, an internal gear mounted to inner periphery of the differential case and a sun gear mounted to the planetary shaft outer periphery.

Engine driving force input from the carrier is transmitted to the sun and internal gears engaged with the pinion gears with torque distribution ratio 41:59*. (*Value in the state with no differential limiting carried out by the LSD mechanism)

Power flow

DCCD: The Center Differential power flow.

Mechanical LSD Mechanism

The torque-sensitive mechanical LSD mechanism consists of a torque cam, main clutch and main clutch hub mounted to the sun gear and planetary shaft. The differential limiting function is achieved by restraining free rotation of the planetary gear unit when the main clutch is engaged with the torque cam.

DCCD: The torque-sensitive mechanical LSD mechanism consists of a torque cam, main clutch and main clutch hub mounted to the sun gear and planetary shaft.